Help:Templates: Difference between revisions
No edit summary |
|||
Line 652: | Line 652: | ||
Above all, learn how to use CSS styles in making your templates, and experiment with their effects. | Above all, learn how to use CSS styles in making your templates, and experiment with their effects. | ||
===Nesting templates=== | ===Nesting templates=== |
Revision as of 14:27, 26 December 2012
This article is a fledgling. Help BoyWiki grow by expanding it |
Templates are pages shown in Portal:Template index. This means any page whose name begins with "Template:", such as "Template:Documentation", can be used as a template. The content of a template can be added to a page by typing {{templatename}} while editing the page. When the page is later viewed, {{templatename}} is replaced by the content of the page "Template:templatename". If the page "Template:templatename" is later altered, all the pages with {{templatename}} in them will change automatically.
Amongst other things, templates are used to add recurring messages to pages in a consistent way, to add boilerplate such as template {{stub}} which indicates that the article is a fledgling.
When a template is automatically expanded and appears on a page, it is said to be "transcluded".
Templates are documented (or should be) at their pages. See Help:Template Documentation
General
Most templates are pages in Portal:Template index
Templates can contain any desired Wikitext, including calls to other templates. They have some limited programming capacities: customizable values (called parameters), calculation and branchings (using parser functions), and access to wiki-specific variables (magic words), such as dates, times, and page names. They may also contain tags which define which parts of the wikitext are to be included when the template is transcluded or substituted. This means that the appearance of the template page itself need not be the same as that of the transcluded content (for example, it can contain documentation, categories, etc. for the template).
How to do it: To transclude a template to an article or page, type {{template name}}
in the wikitext at the place where the template is to appear. The prefix "Template:" need not be included, and an initial capital is not necessary.
Note: Attempting to transclude a template that does not exist produces a red link, just like linking to any other nonexistent page. Following the link allows one to create that particular template.
Also see: Help:Templates for beginners
- TEMPLATES are just blocks of saved text that have been given names. Some are ordinary text paragraphs and some contain wikitext to make headings, indents, tables, and the like. In a simple case, by typing a template's name in the work, an entire block of text is added to the page with all of its formats and other parts, just as if it had been typed by the user. This behavior can be repeated at any point that the user wants, and almost any work that is found on a wiki page could be placed within a template to do this. The main effort as you might suppose, lies in its initial design.
- NAMES of templates are assigned when they are first saved. The name must be unique, and it is used when a template is called for use. Sometimes other text is also used along with the name; it can include any options and parameters.
- OPTIONS allow the user to vary the template's usual behavior.. The usual behavior suits most situations but the designer builds-in ways of changing things just in case. Option values are usually limited to a short list so these are described in a template's documentation. For example, option values for an option called align might include only left, right, or center, and no others. Templates do not always need options, since their default behavior is often enough.
- DEFAULTS are the values used by a template when the user did not say. Default values are specified in design, and they could apply to formats or to user text inputs. For example, in the alignment example above, if the align option was not used, the template could use left, provided that left had been specified in design as its default. In the same way if the user forgets to type a text input, the template could use a pre-planned default input instead of the missing parameter; sometimes just a code to say something was forgotten.
- PARAMETERS are usually bits of text that a user enters for a template to process. For example, if a template makes text red, it still needs to know the text to color; this text is called a parameter, and the text is included by the user when the template is called for use. Sometimes parameters contain text like code to insert an image, or even a gallery or a table; it just depends what the template is designed for. A template can even be the parameter of another template; for example, a template to insert a test paragraph might occupy the parameter space of a template to make a text box. The new paragraph would then appear in a new text box.
- MORE GENERALLY, templates let us do much of the preparation in advance of making a page, and let us insert a block of typing, be it code to make tables, boxes, and other structures, or just a paragraph of text that is used a lot.
Usage syntax
Parameters
The basic transclusion syntax given above can be extended by the addition of parameters, which are used to control the template's output. The syntax for this is
{{template name|parameter|parameter|...}}
where each "parameter" may either contain just a value (these are called unnamed parameters) or be of the form name=value
(named parameters). The first, second, etc. unnamed parameters are equivalent to parameters named "1", "2", etc.
Whitespace characters (spaces, tabs, returns) are stripped from the beginnings and ends of named parameter names and values, but not from the middle: thus {{ ... | myparam = this is a test }}
has the same effect as {{ ... |myparam=this is a test}}
. This does not apply to unnamed parameters, where the whitespace characters are preserved.
What parameters (if any) can or should be passed to a template, and how they are to be named, depends on the coding of that template. Named parameters can be defined in any order. Superfluous or misnamed parameters will be ignored; undefined parameters will be assigned default values. If a parameter is defined more than once, the last value takes effect.
The value of a parameter can be the empty string (pipe or equals sign followed immediately by the next pipe or the closing braces). This is different from leaving the parameter undefined (although templates are often coded so as to behave the same in both cases).
Other details
Template names are exactly like other page names case-sensitive except for the first letter, with spaces indistinguishable from underscores. If the symbol # (normally used to link to a section of a page) appears in a transclusion, then it and any characters that follow it are ignored.
Notice that the same double-brace syntax is used for many MediaWiki variables and parser functions (see Help:Magic words). For example, the code {{NAMESPACE}}
may look like a template call, but it is actually a variable whose value is the namespace prefix of the current page.
Usage hints and workarounds
The following points may be worth noting when using templates:
- An unnamed parameter cannot contain an ordinary equals sign, as this would be interpreted as setting off a named parameter. (This does not apply if the equals sign comes within another template call or other item which the parser handles separately.) To pass an equals sign in an unnamed parameter (for example in a URL with key/value pairs), replace the equals sign with the special template {{=}}, which returns an equals sign that will not be specially interpreted. Another method is to replace the unnamed parameter (and any subsequent unnamed parameters) with named parameters — the first unnamed parameter is equivalent to a named parameter with the name "1", and so on. So to call template
{{done}} with the parameter "a=b", type either {{done|a{{=}}b}}
or {{done|1=a=b}}
.
- Similarly, it is not possible to use an ordinary pipe character | in template parameters, as it will be interpreted as a separator. (Again, this does not apply if it comes within another separately parsed item, such as a piped wikilink.) This time the problem can be solved by using the special template {{!}} in place of the pipe, or (if the pipe is not intended to be parsed specially at a higher level) using the HTML entity |.
- Remember that whitespace characters (spaces, tabs, carriage returns and line feeds) are not automatically stripped from the start and end of unnamed parameters (as they are from named parameters). Including such characters (or any other non-visible characters in any parameters) may in some cases affect the template's behaviour in unexpected ways. (Template designers can use
{{StripWhitespace}} to remove unwanted whitespace in unnamed parameters.)
- In documentation and discussions it is often convenient to be able to produce the template call syntax, with a link to the template in question, but without actually calling the template. This can be done easily using the "
{{tl}}" template (the template link template). For example, using the text "{{tl|tc}}" produces " {{tc}}". There is an extended version, {{tlx}}, which also supports parameters.
- When a template is changed (when the template or one of its subtemplates is edited), the change will be reflected on all pages on which the template is transcluded. However the change may not become visible on all pages immediately — a previously cached version of a page, based on the previous version of the template, may continue to be displayed for some time. Use the purge function to force a page to be displayed using the latest versions of templates. (This includes the template page itself, if it contains usage examples.)
- When viewing old versions of pages, remember that templates will be transcluded as they are now, not necessarily as they were when the old page version was active.
- To list all pages onto which a template is transcluded, use What links here on the template page. (This will not include pages where the template has been substituted.)
- To get a list of templates transcluded on a page, click "Edit", and find the list below the edit window. This list also includes the sub-templates used by the templates that are directly transcluded. To get such a list for a page section, an old version of the page, or your newly edited version prior to saving, click "Show preview" on the appropriate edit page. (For an old version, the subtemplate tree will be constructed according to the templates' current state.)
- There are limits to the number and complexity of the templates that an article may have. See the "Expand limits" section for help in resolving this.
Creating and editing templates
Templates are created and edited in much the same way as any other page: choose an appropriate name, navigate to that page, then click the Edit tab or create a new page as needed. As mentioned above, templates are normally placed in the Template namespace, though templates intended for your own personal use or for experimentation can be created in your own user space. Anything that can be included on a normal page or article can be included on a template, including other templates (called subtemplates). Templates often make use of programming features — parameters, parser functions and other magic words — which allow the transcluded content to vary depending on context. There are also special tags to control which information is transcluded and which is not.
Before creating a template, do a quick search for existing templates (e.g. by exploring Portal:Template index) to see if there's already a template that does what you want, or a similar template whose code can be copied and modified (or left in place and expanded). Look for generic templates on which the new template can be based (for example, navbox templates can be easily created by calling the generic Template:Navbox).
There is no hard rule about what name to choose for a template — make it short but reasonably descriptive. If similar templates exist, try to follow a consistent naming pattern. Templates can be renamed without breaking existing transclusions, provided a redirect to the new template name is left behind.
Be extremely careful when editing existing templates — changes made can affect a large number of pages, often in ways you might not expect.
To propose the deletion of unused or inappropriate templates, or other changes in the way particular templates are used, go to Templates for discussion (TfD).
Handling parameters
The values of the parameters which can be fed to a template are represented in the template code by items enclosed between triple braces:
- the code
{{{xxx}}}
will be replaced by the value of the parameter named xxx - the codes
{{{1}}}
,{{{2}}}
etc. will be replaced by the first, second etc. unnamed parameter (or the value of a parameter named 1, 2, etc.); these are sometimes known as positional parameters
If a parameter is not assigned a value, then the above replacements will not take place — the form "{{{xxx}}}" will remain as the effective value of the parameter. To change this behaviour, define default values using the pipe syntax. For example, {{{1|default}}}
will be replaced by the first unnamed parameter if there is one, or otherwise by the text "default". Similarly, {{{xxx|}}}
will be replaced by the parameter named xxx if it exists, or otherwise will be left blank. Though if a template is called with the parameter specified as empty (e.g. {{Example|}}
), the default for the parameter will be ignored; if that is undesired one can use {{#if:{{{1|}}}|{{{1}}}|default}}
instead to get the text "default" even if the parameter is specified as empty.
Parameters do not get expanded when they are inside nowiki tags or XML-style extension tags. Thus, the following will not work within a template — <myextension xparam={{{tparam}}}> ... </myextension> — because the parameter is not expanded.
Because of the multiple uses of double-brace and triple-brace syntax, expressions can sometimes be ambiguous. It may be helpful or necessary to include spaces to resolve such ambiguity, for example by writing {{ {{{xxx}}} }}
or {{{ {{xxx}} }}}
, rather than typing five consecutive braces. However, watch out for unwanted whitespace appearing in template expansions.
System variables and conditional logic
Template code often makes use of the variables and parser functions described at Help:Magic words, in order to make the template's behaviour depend on the environment (such as the current time or namespace) or on the parameter values which are passed to it. They can also be used for arithmetical calculations. Notice that full string manipulation is not available (although templates have been created which provide such functionality, though very inefficiently and imperfectly), nor are certain standard programming features such as loops and variable assignment.
Some of the most often used variables and functions are listed hereafter. For more, see Help:Magic words.
Description | Text entered | Result |
---|---|---|
Uppercasing text | {{uc: Heavens to BETSY! }} | HEAVENS TO BETSY! |
Lowercasing text | {{lc: Heavens to BETSY! }} | heavens to betsy! |
Getting a namespace name | {{NS: 1 }} | Talk |
Getting a Wikipedia URL | {{fullurl: pagename }} | https://www.boywiki.org/en/Pagename |
The ParserFunctions extension gives more programming-oriented parser functions.
Description | Text Entered | Result |
---|---|---|
Testing between options | {{#ifeq: yes | yes | Hooray...! | Darn...! }} {{#ifeq: yes | no | Hooray...! | Darn...! }} |
Hooray...! Darn...! |
Testing if a parameter is set | {{#if: {{{param|}}} | Hooray...! | Darn...! }} | Darn...! |
Making a calculation (mathematics) [area of circle of radius 4, to 3 decimal places] |
{{#expr: ( pi * 4 ^ 2 ) round 3 }} | 50.265 |
Testing the result of a calculation [is 1230 even or odd?] |
{{#ifexpr: 1.23E+3 mod 2 | Odd | Even }} | Even |
Description | Text Entered | Result (for this help page) |
---|---|---|
Page names | {{PAGENAME}} {{FULLPAGENAME}} |
Templates Help:Templates |
Name of the current namespace | {{NAMESPACE}} | Help |
Number of registered users | {{NUMBEROFUSERS}} | 225 |
Number of pages in a given category | {{PAGESINCATEGORY:"Weird Al" Yankovic albums}} | 0 |
Current software version | {{CURRENTVERSION}} | 1.42.1 |
Timestamp of last revision | {{REVISIONTIMESTAMP}} | 20121226142727 |
Finding and Using Templates
There are already several thousands of templates within the WikiBooks templates namespace. That is another way of saying that the templates list is already long. At first sight, this may seem to avoid the need for template-making, but things are not so simple.
If the name of the template is known, then it can be found easily, but if the name is not known, it can take a long time to find a template similar to the one that you are looking for. Templates have their functions described on their own pages but many do not include notes, so the task of knowing which is which, and what they do even when they are found, becomes doubly difficult.
Templates made in Wikipedia and Wikibooks are not interchangeable, since they exist on separate servers. Although the code to make them is identical, this description applies to finding things in Wikibooks.
- To view lists of templates listed alphabetically within WikiBooks, follow the link to the All Templates Namespace.
- To find templates listed in various template categories, for example, drop-control templates, follow the link to the page Category:Templates.
- If you know a template's name, then find the template page by using the search box on any Wiki page. For example, to find Dropimage just type;
Template:Block then enter.
When a template page is found, the code to make the template can be seen by viewing its editing window. Many pages have their documentation on the same page as the template code, isolated from it with <noinclude></noinclude> tags.
If after searching, you still need to make a template, as many no doubt do, then read on.
Put it on the Page
Templates are called for use in pages by typing a line of Wikitext, and so the user needs to know the correct spelling of the template's name, options, and parameters. Even when these are known it is all too easy to disrupt a page with a template error, especially during trials, so consider using the sandbox for testing. Some templates have all of the documentation and details on the same page and this makes them easy to use. See templates Plainlist, and Codebits as examples.
To call up any template for use in a page, the code is typed within double curly brackets. {{}}.
Included within the curly brackets is the template name, then, if required, a sequence of options, followed by a sequence of parameters. All entries are separated by pipe symbols. (|). For example, the general form to use for a template with two options and one parameter is as follows:
Template:Block
and a typical example of its use is:
Template:Block
The above code has only one parameter; it is numbered 1 by default. Parameters are given numbers or names to identify them in their design code, and examples will be seen in the sections that follow. The template-call in the example uses a so-called unnamed parameter, because it is not preceded by a term like 1= (numbered parameter), or content= (typical named parameter). When templates have several parameters then the parameter numbers or names help to make clear to the template which is which. Alternatively, the template can manage with unnamed and unnumbered parameter entries provided that they are in any case listed in their correct number sequence. When in doubt, use names or numbers. At times, especially when the first character of a parameter is a symbol, the use of named or numbered parameters avoids the corruption that would otherwise result with the unnamed entry.
The sequence of options is unimportant, since all options must be named in any case. Using named values just means adding the name of the option and an equals sign before the option's value. This of course requires a knowledge of the template's details.
Template names are sensitive to case except for the first letter, so a useful convention is to use lower case for template name, parameters, and options all of the time; that way you will never be in doubt.
Parameter names are quite sensitive to case in every way, so a capital letter makes all the difference. As a general rule, do not mix unnamed and named parameters in a template call, since the method used by the program to interpret their meaning becomes confused. Either use all unnamed with special attention to their sequence, or all named in any order that you like.
Find Details from Code
Let us assume that a template made by others has been found but that its details are unclear. Even without much knowledge of mark-up, it is usually possible to discern the options and parameters of a template by inspection of its coding. To see how this can be done follow the reasoning below.
The coding and anything else on a template page can be displayed in the sandbox by typing a special code there. The template does not do anything when this is done; it just reveals the text of the template page. That is, it reveals the coding and any documentation. As an example the template code for say, the template Tocbox, can be viewed in the Sandbox by typing:
Template:Block
To save the reader the trouble of doing so here, the template code for Tocbox is given below.
Code for the Template Tocbox
{| class=toccolours style="margin:1em 0 0 0;width:{{{width|300px}}};" align={{{align|left}}} |
The template page itself has a good description for its use, but assume for a moment that the descriptive material was absent. The code at the top of a template page is always the template source code; consider the example given above. Although it looks complicated, the object here is not to understand it, but to find the options and parameters from the code itself.
Note that the end of the code is marked with a <noinclude> tag, to make sure that any text that follows it is not used as a part of the template. In this example, there are two parameters; they can be recognized as the items with the form:
These entries identify parameters one and two respectively. It is clear, even without much understanding, that the first parameter is the heading text and the second parameter is the content text, and these terms in addition to the numbers could be used as their names . In the event that a user forgets to enter the parameter for say, content, a {{{2}}} will be displayed on the page as a reminder of what is missing.
All of the options within this template are recognized from the typical form;
This extract states that there is an option called align that has the default value of left. The idea of this default is that the value left would be used for align if the user does not use that option in the template call. The option could have almost any name; in fact it has been given the same name as the HTML attribute associated with it, (the part before the equals sign in the main code block). There are several properties within this code but only two of them have been coded as options; align and width, and both options have similar bracket formats to that of the above example.
With the options and parameters now understood, test the template on a page as follows:
This is the code: Template:Block The result is: Template:Tocbox
It should by now be clear that despite having no specification for the template in the first instance, it has been possible to obtain information from the coding for its use.
Modifying a Template
Assume for a moment that a template has been found that is nearly right, but not quite. Say for example that the background color was the only part that was wrong. The source code for such a template could be changed, by adding a term to modify its background color. Then, the modified version could be saved as a new template, with a different name. Note that if the modified template were saved with the same name as before, the existing users who depended on the original colors would experience unwelcome changes in their work.
There is another way that allows the new user to choose colors while the existing users can continue to enjoy the default colors that their work displays. The template can keep the old name if the background property is made into an option, and the original background color made its default. Then, since the old users would not bother to specify the background color, perhaps not even knowing that they now could, they would get the usual color as the default value and would be happy with it. The new users who need a different color, could simply specify it as an option value when they call the template for use. In this way both parties would be content.
The modifying of a template approaches the difficulty of making a new one at times, and this process is covered in other sections below. For the background-change case, a suitable modified Tocbox code module would look like this. The code is:
{| class=toccolours style="margin:1em 0 0 0;width:{{{width|300px}}};background:{{{background|#f9f9f9;}}};" align={{{align|left}}} |
In the above code the background property has been made into an option. In addition, the original background color, #f9f9f9; , (light gray), has been used for the default. To labor the point, if the user does not bother to specify the background color, he will still get the gray color as before. Note again that the added option need not have been called background but could, for example, have been called bgc or some other name. In that event the template's option code would look like background:{{{bgc|#f9f9f9;}}}, and another color would then be called using say, bcg=papayawhip on the page.
The real template Tocbox has not been modified here, though this example provides a reliable demonstration of the method to use for doing so. After the modification above the template could be called by the new users as follows:
A knowledge of CSS property values allows considerable variation in a template's appearance. Luckily, the subject is well documented. See the external W3 site's CSS Reference List for a comprehensive listing of values and properties. Although the examples on the referenced page are designed for style sheets, the syntax found there is also that used for modifying styles within templates and other in-line styles. In addition, a useful color reference can also be had at Web Colors. A drop-box with many of the CSS properties for tables has been provided in the box-making section below. If time is short it could be noted that most of the template work done so far in this project, (WikiBooks that is), could have made do with little more that the CSS properties of text and tables. Study of these two areas is thus rewarding.
CSS reference sources are useful, though styles can also be changed with HTML attributes, (the styles like align with the equals signs). Such attributes can be seen in HTML reference texts as opposed to CSS texts, and in the aforementioned drop-box below. It may be of interest to know that some HTML attributes are the only ways to accomplish certain tasks; examples include colspan (to span table columns), rowspan (to span table rows), and align, (to align tables to center, something that the CSS float property cannot do).
Making Templates
There are many template types, but those used for inserting and modifying text are the most numerous. Boxes feature next; whether they are information boxes, so-called user boxes, or simple text boxes, they all have common constructs. Some templates have dynamic functions, like drop-controls, though once their basic outlines are clear, they can be shaped for many purposes. At least one example of each will be considered.
Template making consists of writing functional code, Wikitext or HTML, or sometimes a mixture of both. The method is to test the code in the Sandbox, until the function works well. Then the options and the parameters can be assigned to the code. These are tested again, and if all is well, the block of code can be saved as a template.
In saving the template it as well to check whether or not there is an existing template of that name already. The simplest way to save a template is as follows. First, make sure that you are logged-on in a page of WikiBooks, to avoid making a template in the wrong project. Go to the search box at the left of the WikiBooks page, and enter the wording to find the as-yet unmade template. Assume here that the intended name is to be Caption. The line to type in the search window is just:
If the template is found, then the name is already taken, and another is needed. Assuming that the name is not found, then the search results window will state that it was not found and ask whether or not you want to make the page. Click the link to make the page.
The link opens a template editing page with the name of the template already listed as its address. Copy the code from your work in the sandbox, then paste it into the empty template page. In the line immediately following the last line in the code block, add the tags <noinclude></noinclude>. All text not intended to be a part of the template code, must be placed between these tags, as is the case for the template's description.
Finally, save the page by pressing the Save page button at the bottom of the page. The template is now made, and can be called into use with its given name. Go to the sandbox and test the features of the template.
Text Paragraphs
The code for a template need not start with any special character or symbol. The main consideration is that the code performs the required action, just as if it were typed directly onto the page. At the 'end of the code block, be sure to add the <noinclude></noinclude> tags as mentioned above.
All of the existing Wikitext and HTML code that can be used in a page can be used for a text template. The user of a page does not have access to the parts associated with styles, namely the heading of the web page and their style sheets. As a result, users are limited to modifying the parts of the page that are available, the text within the body of the page. Those familiar with web page design will know that the only remaining available method is to modify the page's text with in-line styles. Working methods use the <div></div> tags and the <span></span> tags, thanks to a feature of Wikitext that allows the use of HTML coding within it. CSS, (Cascading Style Sheet), properties and values are used within these tags to modify the text styles that would otherwise apply.
It is as well to point out here the difference in use for span and div in text templates. Span should be used to format text only, noting that any formats applied to the text will not extend beyond the last text character; div, on the other hand, will apply its formats to a rectangular block of text that extends across the page. the significance of this is that div is neater for changing background colors on the page. A comparative example can be seen in the Classes and Styles in Tags section of Class and Style Notes.
The Simplest Case
Before doing any formatting, consider the method for making a template from a simple block of text. Type a block of text, with all of its formats and page layout in place, then save the block as a template. It is as simple as that. Such blocks of text find use for test text, such as Lorem Ipsum, a well-known text block of fictitious content used by printers and others in laying out their work. To use such a template just type: Template:Block at any convenient place on a page to produce the text block. This block of text is not pre formatted with hard breaks, so it will wrap within the space where it is typed, and with the default text styles of the page.
Adding Styles
To modify text styles, for example, for the text This is the text, we first place the text within <span></span> tags, like this: Template:Block Then we construct a style statement within the first tag. This example makes the font Garamond, 20 points, colored red. It looks like this: Template:Block and the result will be:
Notice that there is still a closing arrow for the first tag; it is located at the end of the style statement.
Notice also that there are three style rules in the statement, separated by semi-colons; these are font-family:Garamond to set the face of the font, font-size:20pt to set the size of the font, and color:red to set the color of the text.
The style statement starts with the term style=, and the right hand side of the statement is entirely within double quotes.
The individual style rules consist of a property; the left part, and a value; the right part. The two parts are separated by a full colon. The format of a style statement is strict. If the format has an error within it then the whole statement could fail. Note that Wikitext could have been used on the text itself; for example, to produce italics, (double quotes), or text that is bold, (triple quotes). Wikitext acts in addition to the CSS styles, provided that there are no obvious conflicts. Several spans and style statements can be applied to produce quite complex results.
These tag sets can be nested; that is, one set of tags within another set. Beware of nested span tags, since there can be unexpected results. Say that an overall style is applied to several paragraphs using span tags. Within these paragraphs another span set is used to format one of the paragraphs differently. When this is viewed, at the point where the inside span closes, the styles will have reverted to the body text styles described by the style sheet, and not the intended outside style definition. This is perhaps because the first closing tag was wrongly interpreted as the end tag. The problem is avoided by using div tags for both, or at most by using span tags for only one of the formats.
Many properties exist to modify text. They consist of all of the text styles found in style sheets, namely those for fonts, padding, alignment, margins, borders, text colors, and backgrounds. CSS property lists and other material on Fonts and Text provide the source material for all such work. Although CSS properties and examples are listed primarily for style sheets, the properties and values themselves can be used on the page and in templates. The Study Work drop-box contains a useful code module for studying text properties. It contains most of the useful text entries and can be copied for study into the sandbox.
Template:Dropimage
Template:Dropimage
Parameters
Now, continue to make use of the red-text example. Although the code could be saved as a template just as it is, it would not be very useful since it consists only of fixed text. To introduce the notion of variable text chosen by the user, we need to make the text position in the code into a parameter.
Assuming that the basic code works correctly, the parameter brackets can be added. In the above text example there is only one parameter, the content to be formatted. Starting with the code above, just replace the text part so that the code line now looks like this: Template:Block Notice that the original text has now been replaced with: Template:Block The digit identifies the parameter as number one. It is also the name of the parameter. The word content is just a convenient label, though either the number or the label can be used for named parameters. If the user forgets to write any text in a parameter position, then the number of the parameter will appear on the page to remind of it. If the template had more than one parameter, a similar process could be applied, with a sequence of digits 2,3,4 etc., and adding a suitable label in place of content for each.
Saving it in the usual way completes such a template. Assuming that the template were to be saved with the name BigText then the entry to call it for use would be just: Template:Block Note that when a template has several parameters, the ones used can either be entered as named parameters, using the number or label with an equals sign, or as unnamed parameters, by omitting the added names and just entering the text directly. The parameters should be all unnamed or all named but not a mixture of the two. If they are unnamed, the correct sequence must be maintained, and if they are named, then any sequence can be used. Number names and label names can be mixed without difficulty in a template call.
Although virtually any tags can be modified by adding a style statement to the leading tag, it is not to say that the work can always be made into a template. There is at least one exception that exists when it comes to making such a template. The <pre></pre> tags by their very definition cause a template's parameter code to be disregarded, and a different approach is needed. Instead of attempting to make a modified pre-formatted text template consider the use of Prettypre for a ready-made fancy version of these tags.
That is to say, it is possible to modify the <pre></pre> tags with inline styles, to make more interesting pre-formatted text, and it is possible to add the tags to text used as a template's parameter, but making a template from text bounded by pre-formatting tags will prove more difficult.
Options
For completeness, we can also add options to our basic red-text template example. Say we want to change the color of the text from time to time in our work. We could make another complete template for the new color or we could just add an option to the text coloring code. The new code looks like this: Template:Block
Note that the entire property value (applies also to an attribute value), must be enclosed in triple curly brackets. Additionally, the value should be replaced with an option name / default value combination. In this case, if the user does not specify the color of text, it will be red in any case. If it is specified, (see the example below}, it can be changed to any color using the option tint= within the template call. Assuming that this template's name were BigText the template call for purple text would be, say: Template:Block
Other options could be made in the same way, and similar techniques could be used regardless of the tags used for the template.
A knowledge of the different tags and access to lists of CSS properties allows considerable scope in template design.
Making Boxes
The following sections make box or table templates from Wikitext. They can also be made with HTML tables in the same way. When it comes to making such a template, wikitext is fine but when a table is needed to go into a template as its parameter, or part of its parameter, an HTML table should be used instead. The WikiBooks text [[../Tables|Making Tables]] touches on HTML table structures, and explains how to use styles. It is assumed that the reader is familiar with these concepts in the text that follows.
The Box Structure
Boxes are essentially tables, in fact table cells. The CSS property list to format tables is extensive. Simple boxes make use of the table container, and one or two cells within it.
Apart from the table container, the other structures of a table include its rows, and cells. In the case below there are two rows, each with only one cell in them. Each part of a table has properties that affect it, and an example of typical table coding can be seen in the listing below.
{|style="background:lightyellow;width:150px;margin:none;border:1px solid lightgrey" align=left |
Running this code in the sandbox produces the following:
Heading |
Content. |
If necessary, refer to the WikiBooks text [[../Tables|Making Tables]] or the Wikipedia text Help-Table for detailed advice on making tables. Refer also to the drop-down box below for a listing of the commonly used table properties and their meanings.
Template:Tablestyles
For now, it will suffice to note only that:
- A table is enclosed in these symbols: {| |}
- A caption placed above the table starts with a |+.
- A heading cell within the table starts with a !
- A new row is created with the symbols: |-
- A data cell within a row is created with the symbol: |
- Style statements can exist at the table, row, or cell levels.
- An additional pipe symbol separates a cell's styles from its text. |
- Starting tables, rows and cells on new lines avoids many problems in templates.
Follow the reasoning in this description from the code.
The table container has background, width, margin, and border properties, and the align attribute assigned.
- Background;sets the background color for the whole table.
- Width; sets the overall width of the table.
- Margin; removes margins of the table.
- Border: Sets the thickness, type, and color of the table border, all in one.
- Align: Permits the box to be placed on the page at left, right, or center.
The cell in the first row has text-align,padding, and a form of heading text.
- Text-align;positions the cell text horizontally at the center.
- Padding; sets the padding within the first cell for the box heading text.
- The Heading Text; is made bold with Wiki mark-up.
The next row has text-align. This property applies style to all of the cells in the row at once, though not all properties can do this.
- Text-align;justifies text in the bottom cell - the main content.
The content cell has padding, and the content text.
- Padding;sets the spacing around the content text.
- The content text; is the main text for the box template.
Other properties could be specified for this text box, for example, for the details of the fonts to use, but there is enough here for this example.
Parameters and Options
It is intended to provide three options along with the two parameters. The options are to be background,width, and align. The parameter names are to be 1 and 2, with the labels heading and content.
The options and parameters have been added to the code below:
{|style="background:{{{background|lightyellow}}};width:{{{width|150px}}};margin:none;border:1px solid lightgrey" align={{{align|left}}} |
Parameters have been made in place of the heading and content text. The formats for parameters one and two are:
Template:Block
Each parameter format consists of a parameter label,( heading or content), a pipe, symbol,|, and the true name of the parameter, (1 or 2). In each case, both the parameter name and the entire parameter expression are enclosed in triple curly brackets. {{{}}}.
Options have been made for the properties background, width, and align. The formats are :
Template:Block
Notice that the format of the bracketing is similar to the examples given in the making of text templates, and that the same strict format is used to identify the options and parameters.
A parameter can use the option format too. When a parameter does so, it must use the named parameter style in the template call. The advantage of such a parameter is that it can have any default value, including an image. The disadvantage of using the option format for a parameter is that the highly conspicuous numbered reminder is lost. You will recall that the more formal parameter style gives a parameter number as the default.
The template can be saved in the usual way. Assuming that the template were saved with the name Textbox, then it could be called for use by typing the following: Template:Block The variations in boxes are considerable. By adjusting the table structure, it is possible to add images and other effects. Most of the information boxes within Wikipedia and WikiBooks have a table basis for their construction.
Making Drop Controls
Drop-boxes save space on the page and can be used for both text and for images. Within Wikibooks these boxes are dynamic, and clicking the link on the heading of such a box drops it box to show the entire contents section. Clicking the link again restores it to its closed state.
Drop-boxes can be created in two ways. In the past, the way to make them was to use the classes NavFrame, NavHead, and NavContent. These days, the collapsible class can be used for both tables and div boxes, its simplicity has made it a clear choice in the making of drop-boxes. The first section describes briefly the layout for collapsible divs. The remainder of the section is devoted to the version based on the collapsible table; this method is the basis of the ready-made drop-control template Dropimage.
A ready-made template exists for a quite adaptable drop-box; it is Dropimage, though for those who want the details, they are to be had at Sorting and Hiding.
Collapsible Boxes
The basic code for drop-boxes is just:
The above code produces a drop-box that extended across the whole width of the page. collapsible contains the other two sections, title refers to the panel with the link, and body refers to the text box within the drop box itself.
By default, the contents is hidden when the page is loaded. To have the contents shown by default, the user adds "selected" to the class declaration. CSS styles could also be added as shown below and the option-brackets and parameter-brackets for template-making have been shown, as was explained in the previous section:
Changes in layout is obtained by changing styles in any of the sections, but the preferred method, using collapsible tables, is described in the next section.
Collapsible Tables
(currently being rewritten to update for collapsible tables) The panel below shows the HTML and Wikitext code versions of a fairly basic drop-box based on the collapsible box class. The two versions are equivalent, though users who intend to make a template should use the HTML version, since it can have a table as its content without any instability. Nesting tables in Wikitext is problematic.
If, instead of the collapsed state, the selected state is needed on opening the page, then just add the class selected as in the line class="collapsible selected" . The default state is collapsed which need not be added.
The width style in the table line sets the initial width of the table on the page, and with the exception of un-formatted text, the table will expand on opening to accommodate the contents.
The float and align attributes should be avoided for tables because browsers may not support table alignment. Tables can be aligned in a way compatible with most browsers by setting the initial width of the table to 100%, and by wrapping the table inside a div box with its width set to the desired width. For left and right alignment use float on the div box. For center alignment use a margin of auto on the div.
Parameters and Options
The parameter and option brackets are shown in the panel below for an HTML version of the drop-box template, and it will be noted that the method is similar to that used for simple tables in an earlier section. It may be of interest to note that the outermost table is there simply to allow centering of the entire structure, since the collapsible class does not support it.
The above HTML block of code has been saved as the template dropthing, Dropthing, and it can be called for use on a page by typing something along the lines of the following:
The drop-box that is produced with this template call is this: Template:Dropthing
A more complex ready-made template called Dropimage exists for those who need it. It has a large set of individual options, and the facility to add more properties and classes, the coding for which is described next.
Advanced Options
Although the user is always limited by the original template's design, he has some latitude afforded by the pre-planned options. There is a way, however that allows the user to add classes and CSS properties not considered in the original design. For this method to work the designer of the template must anticipate the possible future need for such a change, and add a few extra keystrokes. It is explained below.
Because both class and style declarations are themselves HTML attributes, in the same way as align, cellpadding, and many others, these two can also be made into options.
More Style Options
To modify the template to add user-written style expressions, the template's existing style expression in the table line would be replaced as follows:
Notice that the entire CSS style expression, (but not the attributes that followed it)), are now the default value of the mystyleT option. When this option is used in a template call the quotes for the value expression should not be used.
The typical template call, introducing new properties might then become:
and the result of making this template call is just: Template:Dropthing
Notice that the intended new style statement must be rewritten in its entirety, and that now a new CSS property (color of text), not included in the original design, has been added within the option statement.
If the mystyleT option were not used, the individual options could still be used. If both the expression and the individual values are changed, it would be as well to study the possibility that one will override the other.
The template Dropimage has been modified to include user modification of class and style.
Endpiece
The three example types given in the above sections will hopefully introduce the reader to the making of templates. Bear in mind that there are many aspects of templates not discussed here; for example, the notions of conditional behavior, loops, and defaults that themselves run as templates. Further reading about templates can be found in the links below.
Above all, learn how to use CSS styles in making your templates, and experiment with their effects.
Nesting templates
Templates may contain other templates — this is usually called "nesting". As the template is processed, the wikitext produced by any nested templates is transcluded into the nesting template, so that the final product is essentially processed from the most deeply nested template out. While fairly straightforward in application, it involves some noteworthy quirks and tricks.