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Template Rendering

Welcome to the AMIS documentation. In this section, we will explore the template rendering feature in AMIS, which is a function borrowed from other template engines, aimed at providing flexibility in rendering text and data structures.

Template Strings: A Combination of Simplicity and Power​

AMIS supports template strings, allowing you to embed variables directly into the text. Here's how to output simple text:

{
  "type": "page",
  "data": {
    "text": "World!"
  },
  "body": "Hello ${text}"
}

The output will be:

Hello World!

Template Strings​

  • When parsing template strings, if the $ character is encountered, AMIS will attempt to parse the variable and replace the template variable. For example, if the value of the name variable is Rick, and the template is my name is ${name}, then the final template will be parsed as my name is Rick.
{
  "type": "page",
  "data": {
    "name": "Rick"
  },
  "body": "my name is ${name}"
}
  • Supports chained value access: AMIS supports using . for chained value access, meaning you can access properties within nested objects. For example:
{
  "type": "page",
  "data": {
    "name": "rick",
    "company": {
      "name": "baidu",
      "department": "it"
    }
  },
  "body": {
    "type": "tpl",
    "tpl": "my name is ${name}, I work for ${company.name}"
  }
}

Rendering HTML with Template Strings​

To render HTML, use the same data mapping syntax: ${xxx}. If the variable itself contains HTML, apply the raw filter for correct rendering.

{
  "data": {
    "text": "<b>World!</b>"
  },
  "type": "page",
  "body": "<h1>Hello</h1> <span>${text|raw}</span>"
}

Expressions​

Supports simple expressions and formula calls. For example:

{
  "type": "tpl",
  "tpl": "${xxx == 1 ? 'One' : 'Others'}"
}

See the expressions chapter for details.

JavaScript Template Engine​

AMIS also supports the JavaScript template engine, internally using lodash template. Note the difference in accessing data scope variables: use data.xxx instead of ${xxx}. This engine treats the data scope as the current code execution context, requiring data.xxx to retrieve values.

The syntax is similar to EJS, <% ... %> indicates JavaScript statements. Familiarity with JavaScript makes page rendering a breeze. Additionally, several JavaScript methods are available, such as formatDate, formatTimeStamp, formatNumber, and countDown.

tip

Template strings and the JavaScript template engine cannot be used interchangeably. For example:

{
  "type": "tpl",
  "tpl": "${data.xxx === 'a'}" // Wrong!
}
{
  "type": "tpl",
  "tpl": "${xxx === 'a'}" // Correct
}

Filters​

Data filters are an extension of the data mapping feature, allowing for additional processing of retrieved data.

  • Basic Usage: ${xxx |filter1 }, for example {name|trim}
  • Filter Chaining: Multiple filters can be chained, such as ${xxx | filter1 | filter2 | ...}, to implement complex data processing flows.
  • Function Call Syntax: It is recommended to use function call syntax for data filtering, for example, replacing ${xxx | html} with ${html(xxx)}. Of course, nested calls like ${trim(html(xxx))} are possible.

Filter Parameters​

Filters can have parameters written into them: ${variable | filter:parameter1:parameter2:.....} If I want to convert the input time to a specific format, I need to specify parameters such as: YYYY-MM-DD

{
  "type": "page",
  "data": {
    "now": 1586865590
  },
  "body": {
    "type": "tpl",
    "tpl": "now is ${now|date:YYYY-MM-DD}"
  }
}

Of course, you can also use multiple filters with multiple parameters:

${xxx [|filter1[:arg1][:arg2]...[|filter2...]] }

Filter List Documentation​

There are many filters:

html, raw, json, toJson, toInt, toFloat, date, now, toDate, dateModify, fromNow, number, trim, percent, round, truncate, url_encode, url_decode, default, split, join, sortBy, topAndOther, unique, first, last, nth, pick, objectToArray, plus, minus, times, division, sum, abs, duration, bytes, asArray, lowerCase, upperCase, substring, base64Encode, base64Decode, isTrue, isFalse, isMatch, notMatch, isEquals, notEquals, map, filter

For more details, see AMIS Official Website - Filters